Fix grammar error in HR Training Results (#9076)

* Fix Typo in message

Issue #9074

* Added  condition for notifying user of grade.
diff --git a/erpnext/hr/doctype/training_result/training_result.py b/erpnext/hr/doctype/training_result/training_result.py
index 16b76a7..36c3cb9 100644
--- a/erpnext/hr/doctype/training_result/training_result.py
+++ b/erpnext/hr/doctype/training_result/training_result.py
@@ -13,7 +13,9 @@
 	
 	def send_result(self):
 		for emp in self.employees:
-			message = "Thank You for attending {0}. You grade is {1}".format(self.training_event, emp.grade)
+			message = "Thank You for attending {0}.".format(self.training_event)
+			if emp.grade: 
+				message = message + "Your grade: {0}".format(emp.grade)
 			frappe.sendmail(frappe.db.get_value("Employee", emp.employee, "company_email"), \
 				subject=_("{0} Results".format(self.training_event)), \
 				content=message)